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Mon, 6 Jan 2020 00:48:08 +0000 Received: from localhost.localdomain (136.49.227.119) by SN4PR0701CA0020.namprd07.prod.outlook.com (2603:10b6:803:28::30) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.20.2602.13 via Frontend Transport; Mon, 6 Jan 2020 00:48:06 +0000 From: Jeff LaBundy To: "lee.jones@linaro.org" , "dmitry.torokhov@gmail.com" , "thierry.reding@gmail.com" , "jic23@kernel.org" , "devicetree@vger.kernel.org" CC: "linux-input@vger.kernel.org" , "u.kleine-koenig@pengutronix.de" , "linux-pwm@vger.kernel.org" , "knaack.h@gmx.de" , "lars@metafoo.de" , "pmeerw@pmeerw.net" , "linux-iio@vger.kernel.org" , "robh+dt@kernel.org" , "mark.rutland@arm.com" , Jeff LaBundy Subject: [PATCH v3 7/7] iio: position: Add support for Azoteq IQS624/625 angle sensors Thread-Topic: [PATCH v3 7/7] iio: position: Add support for Azoteq IQS624/625 angle sensors Thread-Index: AQHVxCr1epeZE2lp7EG7ASuCK0LX4Q== Date: Mon, 6 Jan 2020 00:48:06 +0000 Message-ID: <1578271620-2159-8-git-send-email-jeff@labundy.com> References: <1578271620-2159-1-git-send-email-jeff@labundy.com> In-Reply-To: <1578271620-2159-1-git-send-email-jeff@labundy.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-clientproxiedby: SN4PR0701CA0020.namprd07.prod.outlook.com (2603:10b6:803:28::30) To SN6PR08MB5053.namprd08.prod.outlook.com (2603:10b6:805:78::25) authentication-results: spf=none (sender IP is ) smtp.mailfrom=jeff@labundy.com; 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x-microsoft-antispam-message-info: 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 MIME-Version: 1.0 X-OriginatorOrg: labundy.com X-MS-Exchange-CrossTenant-Network-Message-Id: 0d5e57c0-3368-4677-f870-08d792421820 X-MS-Exchange-CrossTenant-originalarrivaltime: 06 Jan 2020 00:48:06.8714 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 00b69d09-acab-4585-aca7-8fb7c6323e6f X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: y/Kcik1f5x+g1eNOwDczCVw+2DvVWxzOMqkousiZgQcacPO4TRrcN7C5As/TRya/UApH80vKi9F9ueWET8UAGg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN6PR08MB5629 Sender: linux-pwm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pwm@vger.kernel.org This patch adds support for the Azoteq IQS624 and IQS625 angular position sensors, capable of reporting the angle of a rotating shaft down to 1 and 10 degrees of accuracy, respectively. This patch also introduces a home for linear and angular position sensors. Unlike resolvers, they are typically contactless and use the Hall effect. Signed-off-by: Jeff LaBundy Reviewed-by: Jonathan Cameron --- Changes in v3: - Added Reviewed-by trailer Changes in v2: - Merged 'Copyright' and 'Author' lines into one in introductory comments - Replaced 'error' with 'ret' throughout - Added iqs624_pos_angle_en and iqs624_pos_angle_get to remove duplicate logic previously used throughout - Refactored the logic in iqs624_pos_notifier and added a lock to safely evaluate variables that may change in response to user action - Refactored the logic in iqs624_pos_read_raw - Added a lock to iqs624_pos_read_event_config to account for cases in which the corresponding hardware state is in the process of being updated - Refactored the logic in iqs624_pos_write_event_config and read the initial angle in case it changed since having first been read in iqs624_pos_init - Removed iqs624_pos_init as its logic has since been absorbed elsewhere - Removed devm_add_action_or_reset failure message - Eliminated tabbed alignment of platform_driver struct members - Changed Kconfig "depends on" logic to MFD_IQS62X || COMPILE_TEST drivers/iio/Kconfig | 1 + drivers/iio/Makefile | 1 + drivers/iio/position/Kconfig | 19 +++ drivers/iio/position/Makefile | 7 + drivers/iio/position/iqs624-pos.c | 284 ++++++++++++++++++++++++++++++++++++++ 5 files changed, 312 insertions(+) create mode 100644 drivers/iio/position/Kconfig create mode 100644 drivers/iio/position/Makefile create mode 100644 drivers/iio/position/iqs624-pos.c -- 2.7.4 diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig index 5bd5185..d5c073a 100644 --- a/drivers/iio/Kconfig +++ b/drivers/iio/Kconfig @@ -88,6 +88,7 @@ source "drivers/iio/orientation/Kconfig" if IIO_TRIGGER source "drivers/iio/trigger/Kconfig" endif #IIO_TRIGGER +source "drivers/iio/position/Kconfig" source "drivers/iio/potentiometer/Kconfig" source "drivers/iio/potentiostat/Kconfig" source "drivers/iio/pressure/Kconfig" diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile index bff682a..1712011 100644 --- a/drivers/iio/Makefile +++ b/drivers/iio/Makefile @@ -31,6 +31,7 @@ obj-y += light/ obj-y += magnetometer/ obj-y += multiplexer/ obj-y += orientation/ +obj-y += position/ obj-y += potentiometer/ obj-y += potentiostat/ obj-y += pressure/ diff --git a/drivers/iio/position/Kconfig b/drivers/iio/position/Kconfig new file mode 100644 index 0000000..eda67f0 --- /dev/null +++ b/drivers/iio/position/Kconfig @@ -0,0 +1,19 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Linear and angular position sensors +# +# When adding new entries keep the list in alphabetical order + +menu "Linear and angular position sensors" + +config IQS624_POS + tristate "Azoteq IQS624/625 angular position sensors" + depends on MFD_IQS62X || COMPILE_TEST + help + Say Y here if you want to build support for the Azoteq IQS624 + and IQS625 angular position sensors. + + To compile this driver as a module, choose M here: the module + will be called iqs624-pos. + +endmenu diff --git a/drivers/iio/position/Makefile b/drivers/iio/position/Makefile new file mode 100644 index 0000000..3cbe7a7 --- /dev/null +++ b/drivers/iio/position/Makefile @@ -0,0 +1,7 @@ +# +# Makefile for IIO linear and angular position sensors +# + +# When adding new entries keep the list in alphabetical order + +obj-$(CONFIG_IQS624_POS) += iqs624-pos.o diff --git a/drivers/iio/position/iqs624-pos.c b/drivers/iio/position/iqs624-pos.c new file mode 100644 index 0000000..af629bf5 --- /dev/null +++ b/drivers/iio/position/iqs624-pos.c @@ -0,0 +1,284 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Azoteq IQS624/625 Angular Position Sensors + * + * Copyright (C) 2019 Jeff LaBundy + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define IQS624_POS_DEG_OUT 0x16 + +#define IQS624_POS_SCALE1 (314159 / 180) +#define IQS624_POS_SCALE2 100000 + +struct iqs624_pos_private { + struct iqs62x_core *iqs62x; + struct notifier_block notifier; + struct mutex lock; + bool angle_en; + u16 angle; +}; + +static int iqs624_pos_angle_en(struct iqs62x_core *iqs62x, bool angle_en) +{ + unsigned int event_mask = IQS624_HALL_UI_WHL_EVENT; + + /* + * The IQS625 reports angular position in the form of coarse intervals, + * so only interval change events are unmasked. Conversely, the IQS624 + * reports angular position down to one degree of resolution, so wheel + * movement events are unmasked instead. + */ + if (iqs62x->dev_desc->prod_num == IQS625_PROD_NUM) + event_mask = IQS624_HALL_UI_INT_EVENT; + + return regmap_update_bits(iqs62x->map, IQS624_HALL_UI, event_mask, + angle_en ? 0 : 0xFF); +} + +static int iqs624_pos_notifier(struct notifier_block *notifier, + unsigned long event_flags, void *context) +{ + struct iqs62x_event_data *event_data = context; + struct iqs624_pos_private *iqs624_pos; + struct iqs62x_core *iqs62x; + struct iio_dev *indio_dev; + u16 angle = event_data->ui_data; + s64 timestamp; + int ret; + + iqs624_pos = container_of(notifier, struct iqs624_pos_private, + notifier); + indio_dev = iio_priv_to_dev(iqs624_pos); + timestamp = iio_get_time_ns(indio_dev); + + iqs62x = iqs624_pos->iqs62x; + if (iqs62x->dev_desc->prod_num == IQS625_PROD_NUM) + angle = event_data->interval; + + mutex_lock(&iqs624_pos->lock); + + if (event_flags & BIT(IQS62X_EVENT_SYS_RESET)) { + ret = iqs624_pos_angle_en(iqs62x, iqs624_pos->angle_en); + if (ret) { + dev_err(indio_dev->dev.parent, + "Failed to re-initialize device: %d\n", ret); + ret = NOTIFY_BAD; + } else { + ret = NOTIFY_OK; + } + } else if (iqs624_pos->angle_en && (angle != iqs624_pos->angle)) { + iio_push_event(indio_dev, + IIO_UNMOD_EVENT_CODE(IIO_ANGL, 0, + IIO_EV_TYPE_CHANGE, + IIO_EV_DIR_NONE), + timestamp); + + iqs624_pos->angle = angle; + ret = NOTIFY_OK; + } else { + ret = NOTIFY_DONE; + } + + mutex_unlock(&iqs624_pos->lock); + + return ret; +} + +static void iqs624_pos_notifier_unregister(void *context) +{ + struct iqs624_pos_private *iqs624_pos = context; + struct iio_dev *indio_dev = iio_priv_to_dev(iqs624_pos); + int ret; + + ret = blocking_notifier_chain_unregister(&iqs624_pos->iqs62x->nh, + &iqs624_pos->notifier); + if (ret) + dev_err(indio_dev->dev.parent, + "Failed to unregister notifier: %d\n", ret); +} + +static int iqs624_pos_angle_get(struct iqs62x_core *iqs62x, unsigned int *val) +{ + int ret; + __le16 val_buf; + + if (iqs62x->dev_desc->prod_num == IQS625_PROD_NUM) + return regmap_read(iqs62x->map, iqs62x->dev_desc->interval, + val); + + ret = regmap_raw_read(iqs62x->map, IQS624_POS_DEG_OUT, &val_buf, + sizeof(val_buf)); + if (ret) + return ret; + + *val = le16_to_cpu(val_buf); + + return 0; +} + +static int iqs624_pos_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct iqs624_pos_private *iqs624_pos = iio_priv(indio_dev); + struct iqs62x_core *iqs62x = iqs624_pos->iqs62x; + unsigned int scale = 1; + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = iqs624_pos_angle_get(iqs62x, val); + if (ret) + return ret; + + return IIO_VAL_INT; + + case IIO_CHAN_INFO_SCALE: + if (iqs62x->dev_desc->prod_num == IQS625_PROD_NUM) { + ret = regmap_read(iqs62x->map, IQS624_INTERVAL_DIV, + &scale); + if (ret) + return ret; + } + + *val = scale * IQS624_POS_SCALE1; + *val2 = IQS624_POS_SCALE2; + return IIO_VAL_FRACTIONAL; + + default: + return -EINVAL; + } +} + +static int iqs624_pos_read_event_config(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + enum iio_event_type type, + enum iio_event_direction dir) +{ + struct iqs624_pos_private *iqs624_pos = iio_priv(indio_dev); + int ret; + + mutex_lock(&iqs624_pos->lock); + ret = iqs624_pos->angle_en; + mutex_unlock(&iqs624_pos->lock); + + return ret; +} + +static int iqs624_pos_write_event_config(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + enum iio_event_type type, + enum iio_event_direction dir, + int state) +{ + struct iqs624_pos_private *iqs624_pos = iio_priv(indio_dev); + struct iqs62x_core *iqs62x = iqs624_pos->iqs62x; + unsigned int val; + int ret; + + mutex_lock(&iqs624_pos->lock); + + ret = iqs624_pos_angle_get(iqs62x, &val); + if (ret) + goto err_mutex; + + ret = iqs624_pos_angle_en(iqs62x, state); + if (ret) + goto err_mutex; + + iqs624_pos->angle = val; + iqs624_pos->angle_en = state; + +err_mutex: + mutex_unlock(&iqs624_pos->lock); + + return ret; +} + +static const struct iio_info iqs624_pos_info = { + .read_raw = &iqs624_pos_read_raw, + .read_event_config = iqs624_pos_read_event_config, + .write_event_config = iqs624_pos_write_event_config, +}; + +static const struct iio_event_spec iqs624_pos_events[] = { + { + .type = IIO_EV_TYPE_CHANGE, + .dir = IIO_EV_DIR_NONE, + .mask_separate = BIT(IIO_EV_INFO_ENABLE), + }, +}; + +static const struct iio_chan_spec iqs624_pos_channels[] = { + { + .type = IIO_ANGL, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .event_spec = iqs624_pos_events, + .num_event_specs = ARRAY_SIZE(iqs624_pos_events), + }, +}; + +static int iqs624_pos_probe(struct platform_device *pdev) +{ + struct iqs62x_core *iqs62x = dev_get_drvdata(pdev->dev.parent); + struct iqs624_pos_private *iqs624_pos; + struct iio_dev *indio_dev; + int ret; + + indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*iqs624_pos)); + if (!indio_dev) + return -ENOMEM; + + iqs624_pos = iio_priv(indio_dev); + iqs624_pos->iqs62x = iqs62x; + + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->dev.parent = &pdev->dev; + indio_dev->channels = iqs624_pos_channels; + indio_dev->num_channels = ARRAY_SIZE(iqs624_pos_channels); + indio_dev->name = iqs62x->dev_desc->dev_name; + indio_dev->info = &iqs624_pos_info; + + mutex_init(&iqs624_pos->lock); + + iqs624_pos->notifier.notifier_call = iqs624_pos_notifier; + ret = blocking_notifier_chain_register(&iqs624_pos->iqs62x->nh, + &iqs624_pos->notifier); + if (ret) { + dev_err(&pdev->dev, "Failed to register notifier: %d\n", ret); + return ret; + } + + ret = devm_add_action_or_reset(&pdev->dev, + iqs624_pos_notifier_unregister, + iqs624_pos); + if (ret) + return ret; + + return devm_iio_device_register(&pdev->dev, indio_dev); +} + +static struct platform_driver iqs624_pos_platform_driver = { + .driver = { + .name = IQS624_DRV_NAME_POS, + }, + .probe = iqs624_pos_probe, +}; +module_platform_driver(iqs624_pos_platform_driver); + +MODULE_AUTHOR("Jeff LaBundy "); +MODULE_DESCRIPTION("Azoteq IQS624/625 Angular Position Sensors"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:" IQS624_DRV_NAME_POS);